On many machines, especially Venetian blind production machines, a number of tool units must be set in different positions along a machine bed. In some cases, it is advantageous that these tool units be movable relative to one another along the machine bed, such that they can be placed in optionally selectable and yet relatively proportional positions along the machine bed. One instance of this requirement is the Venetian blind production machine which constitutes the subject matter of the European Patent EP-B-0,182,805 (see also corresponding U.S. Pat. No. 4,665,599). This machine comprises a feeding device for supplying from a supply reel at least one metal strip intermittently in the longitudinal direction of the metal strip through a number of ladder tapes, and a punching station with means for punching lift-cord holes in the free end portion of the metal strip before this end portion is inserted in the ladder tapes. The machine also includes a separating station for separating from the free end portion of the metal strip the individual Venetian blind slats inserted in the ladder tapes. The punching station of this Venetian blind production machine has at least two groups of punching tools for simultaneously punching lift cord holes in at least two successive Venetian blind slats, and the separating station has at least a corresponding number of separating punches for simultaneously separating Venetian blind slats for the same number of simultaneously produced Venetian blinds. For readjustment of such a Venetian blind production machine for different slat lengths, the different tools must be set in exact positions along the machine bed. This operation is time-consuming, and errors are easily made. If the punching of lift-cord holes takes place in a machine section ahead of the threading tools, the setting operation will be far more complicated and even more time-consuming.